A wide range of goods are made using asbestos fibres, but it is well known that asbestos fibres are particularly damaging to the health of people working on such production lines. For this reason, various attempts have been made to replace asbestos fibres with less dangerous substances such as ceramic fibres, rock fibres, carbon fibres, glass fibres, synthetic fibres, etc.
Particular attention has been paid to continuous glass fibre yarns made up from individual filaments of great length and of fineness lying between 4 microns and 20 microns. These filaments can simply be twisted together to obtain a plain or twisted yarn, useable in the manufacture of cloth, braid, cord, etc. The resulting goods are nevertheless of inferior quality when compared with goods based on asbestos fibres, and they cannot compete with them effectively.
Attention has also been paid to ceramic fibres and to carbon fibres, but using such fibres increases costs very greatly.
Up to the present, no material has been found which is less dangerous than asbestos fibre, but which has comparable or superior mechanical and physical properties, while not increasing costs.
Proper application of the present invention goes at least some of the way to meeting the above requirements.